While walking barefoot in the woods, Joe stepped on a thorn that penetrated through the sole of his foot to the dermis. How many layers of epidermis did the thorn penetrate? A. 1 B. 2 C. 3 D. 4 E 5?
E) 5 layers of epidermis
There are two main types of epidermis:
Thin , which is found in places like your eyelids and consists of 4 layers (or strata) (Corneum, Granulosum, Spinosum and Basal/e)
Thick, which is found in areas that experience a lot of wear and tear (like the heels and soles of your feet). Thick skin has five layers because of an additional layer known as Stratum Lucidum.
As it is the sole of his foot, we know there are 5 layers, and as we know it reaches the dermis, it must have penetrated all layers of the epidermis (the dermis is beneath the epidermis). So, it has penetrated all layers of a thick epidermis - hence the answer is 5.